1. Field of the Invention
The present invention relates to a solar cell module including at least a solar cell element, a front surface member and a back surface member, and more particularly to such a solar cell module with a configuration tailored to facilitate classification, collection and recycling, and a power generation apparatus employing such a solar cell module. The present invention also relates to separating and recycling methods for such a solar cell module.
2. Related Background Art
Solar cell modules have recently been employed in various forms; for example, there is known the building material integrated type solar cell module, formed by placing a photovoltaic element on a roofing steel plate and covering the photovoltaic element with an encapsulant. Such solar cell modules may become unnecessary when the house provided with the solar cell modules as the building material is rebuilt, or the solar cell modules may have to be exchanged or replaced as the metal substrate may be corroded or the surface material at the light receiving side may be damaged after prolonged use. In disposing of such unnecessary solar cell modules, environmental contamination may result unless the components of the solar cell module are suitably separated, classified and disposed of. It is desirable, therefore, that solar cell modules be separable into their components.
Also from the ecological standpoint, it is required to separate solar cell modules into recyclable components and to recycle such components.
In the conventional solar cell module, however, it is not easy to separate the components, since the module is formed by encapsulating the solar cell element between the back surface member and the front surface member with a resinous sealant.
A solar cell module with a partially separable structure is disclosed in Japanese Patent Application Laid-open No. 5-291603. Such a solar cell module is composed of a solar cell, a solar cell holding member provided in the edge portion at the light-receiving side of the solar cell, and a container provided at the back side of the solar cell; the solar cell holding member and the container are combined with screws. The solar cell module can be separated by unscrewing into the solar cell, the solar cell holding member and the container, but the major part of the surface of the solar cell, being exposed at the outermost surface of the module, is often damaged at the surface after a certain period of use. In such a case, the recycling of the solar cell is not practical, and such a solar cell module cannot be considered satisfactory with respect to recycling potential.
Now there will be explained, with reference to FIG. 5, the current and future process for the collected solar cell module.
The "used solar cell module" that has become unnecessary, for example, by the re-building of the house in which the solar cell module is installed or the "broken solar cell module" that has become unusable by corrosion of the components or by damage on the front surface member at the light receiving side after prolonged outdoor use is "collected", for example, by collecting shops.
Conventionally processes such as "incineration", "disposal" and "dumping into ground" have been executed.
However, in consideration of the environment and the conservation of resources, there is required a process designed for recycling.
There can be conceived a recycling process consisting, after "collection" of the module, of "crushing" of the module, "classification" of the crushed products and "recycling" of the necessary materials. However, such a recycling process, though being capable of reducing the effects on the environment, is costly and is insufficient in resource saving.
Also, in most of the commercial solar cell modules, the front surface member, the back surface member, the solar cell element and the internal filter (for example, EVA) constituting such a solar cell module have respectively different service lives; the most expensive solar cell element has the longest service life in comparison with other components. For this reason, it has long been desired to extract and re-use the solar cell element alone.